Rails 3-回形针：未初始化的常量ActionDispatch :: Request :: UploadedFile

Question

I have a confusing error:

I run Rails 3.0.0 on Ruby 1.9.2 with Paperclip 2.3.5.

When I upload a file I get a 500 error.

NameError (uninitialized constant ActionDispatch::Request::UploadedFile):
  config/initializers/fix_params.rb:13:in `normalize_parameters'
  config/initializers/fix_params.rb:19:in `block in normalize_parameters'
  config/initializers/fix_params.rb:19:in `each'
  config/initializers/fix_params.rb:19:in `normalize_parameters'
  config/initializers/fix_params.rb:19:in `block in normalize_parameters'
  config/initializers/fix_params.rb:19:in `each'
  config/initializers/fix_params.rb:19:in `normalize_parameters'

Rendered /Users/vjmayr/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.0/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (10.2ms)

---

I have seen similar things happen with Rails 3.0.2 and .3 but I have no idea why it happens here. Con anyone help me with finding the problem?

Thanks! Valentin

ADDED config/initializers/fix_params.rb:

module ActionController
  class Request
    private

      # Convert nested Hashs to HashWithIndifferentAccess and replace
      # file upload hashs with UploadedFile objects
      def normalize_parameters(value)
        case value
        when Hash
          if value.has_key?(:tempfile)
            upload = value[:tempfile]
            upload.extend(UploadedFile)
            upload.original_path = value[:filename]
            upload.content_type = value[:type]
            upload
          else
            h = {}
            value.each { |k, v| h[k] = normalize_parameters(v) }
            h.with_indifferent_access
          end
        when Array
          value.map { |e| normalize_parameters(e) }
       else
          value.force_encoding(Encoding::UTF_8) if value.respond_to?(:force_encoding)
          value
         end
      end
  end
end

Answer 1

tadman (Thanks!) pointed me towards the right solution: All I had to do was change the value from tempfile to to_tempfile. This prabably won't happen to too many people, but I thought I'd mention as there has been a similar discussion around that due to a recent change in stable rails 3.0.3 by tenderlove, which is philisophically absolutely correct - but threw off some people...

So here is the changed fragment of fix_params.rb

...
if value.has_key?(:to_tempfile)
        upload = value[:to_tempfile]
...

Cheers,

Val